Lesson 4: Solvation and Hydration Enthalpies
This lesson delves into the energetic aspects of s-block compounds dissolving in water.
- Hydration Enthalpy: This is the energy released when one mole of gaseous ions dissolves in water to form hydrated ions. Hydration enthalpy is a key factor that determines the solubility of a salt.
- Trends: Students will learn that hydration enthalpy generally decreases down a group as the size of the ion increases.
- Solubility: The solubility of s-block salts depends on the balance between their lattice enthalpy and hydration enthalpy. This is why the solubility trends for compounds like sulfates () and hydroxides () are different. For example, the solubility of sulfates decreases down Group 2, while the solubility of hydroxides increases.
